Use a paper gasket on rear diff or not?

[tailgunn]

I had a leaky rear diff, mainly because the previous moron that worked on it didn't tighten the bolts and only used a paper gasket, no RTV. So I fixed it using a paper gasket with RTV on both sides, and properly torqued the bolts.

So I dropped in to a buddies shop this morning on the way to work and told him about the loose diff cover with no RTV- he said I made a mistake, and should not have used the paper diff. I should only use RTV, and in fact, the factory never uses paper gaskets. I have always used a paper gasket with RTV. He said it is going to leak... so, was I wrong?

[Daryl Z71]

I currently have a paper gasket with no silicon being used on my truck with no issues. It's been on there for well over 2 years now. When I did a fluid change on the 2011 truck I use to have it had a paper gasket on it from the factory. I put the exact one back on that truck without any issues as well.

[007matman]

I never use gaskets. Black RTV works just fine and no leaks (ever). Not sure why you'd want to use a gasket as it increases the potential for failures (more things that can fail..

 

Think if it, you have two layers of RTV plus the gasket. That's three potential failure points versus one if you only use RTV. Cleanup and re-application would be the same process.

 

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[tailgunn]

I have never had a paper one leak either, aside from this one that the PO did improperly... but maybe I just haven't kept a vehicle long enough for it to fail.

[tbarn]

I hate it when I see a gasket plus silicone. Seems like a lack of confidence by the person doing the repair. There is a gasket for a reason. Pick one and go with it. GM used paper gaskets for decades without much problem. They have also used only silicone in some instances.

[tailgunn]

So we'll call this an interesting experiment. If it fails, I'll let you know.

[MaverickZ71]

My 96 Impala SS's rear positraction diff came from the factory with a thin 'cardboard' gasket. Replaced it with a Fel-Pro one during maintenance. The Fel-Pro gasket came with little holes cutout on the sides to allow more lube to go down the axle tubes, where the factory gasket did not. I never could get a straight answer on using RTV with the Fel-Pro, so I used it anyway. Never leaked afterwards, whereas the original factory gasket 'sweated' a little.

[sdeeter19555]

Buy a reusable rubber one...

 

I always used Permatex Hi-Tack spray or Gasket Shellac on paper gaskets.

 

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[2018GMC]

I've used diff cover gaskets (no RTV) on my 79 and 97. Both are bone dry on outside. I'd rather use gasket so when I change diff again i don't have to scrape RTV off.

[dasimmon]

I've used diff cover gaskets (no RTV) on my 79 and 97. Both are bone dry on outside. I'd rather use gasket so when I change diff again i don't have to scrape RTV off.

 

that was my thinking

[barry G]

the real gasket, it only looks like paper. There is a reaction to gear oil that finishes it off. It may even look like it is leaking black goo at first install and fill.

 

that is the "glue" of the seal taking shape.

Drive it around until full warm..

 

FelPro does good. Factory does too.

 

the covers are different metal than the casting, and yet the whole shape is the strength of the pumpkin. the gasket is the brain keeping it together.

 

I was a quick lube guy...lots of rear diffs.

american stuff is super easy.

 

My own drove a hole through the cover at 20 years and 340 something k miles. Just the oil splashing burrowed a hole.

A new cover will be the most stubborn. Let the black magic goo dribble.. it always wins.